3thk is a 4 chain structure with sequence from Rattus norvegicus. This structure supersedes the now removed PDB entry 2pqh. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
SPTN1_RAT Fodrin, which seems to be involved in secretion, interacts with calmodulin in a calcium-dependent manner and is thus candidate for the calcium-dependent movement of the cytoskeleton at the membrane.